So I've been using avltree & gensetdyn (amongst others) lately in a
little project of mine, and I have some questions:

- When using avltree_iter() we need to pass a avliterfunc_t_ref, which
  takes 3 arguments. If I understand correctly, first is the uint32_t
  index, then the tree's "internal" (unsigned int) index, and my

  So if I wanted, from there, to remove an item from the avltree, I
  could either use avltree_deletenode(tree, ARG2) or
  avltree_delete(tree, KEY) where KEY is the one from dtok(ARG1,p) --
  would all that be correct, or did I miss/misunderstood something?

- So it means avltree_deletenode() needs the avltree's own/internal
  index, whereas gensetdyn_delete() needs "our" uint32_t index,
  I.e. if I have that uint32_t and want to remove things from both the
  avltree & gensetdyn (I'm using the later to store the actual data
  indexed via the former, btw) then for avltree I need to get the key
  (e.g. via t->dtok(u,p))

- I think there's a bug in skalibs right now, avltree_deletenode() is
  broken and things don't even compile; I believe the attached patch is
  a correct fix for it.
  (I ended up using avltree_delete directly, guessing you usually do
  that as well maybe?)

- And on a completely unrelated topic, is there really no way
  (macro/function) in skalibs to remove an item from a genalloc? I get
  it for stralloc, it's not really thought of as an array but a string,
  you rarely want to remove one char from somehere in the middle, whatever.

  But with a genalloc, I'd expect one to (often) be wanting to remove an
  item from the array, and not always/only the last one, yet I can't see
  how that's supposed to be done? (Again, as in via a macro or
  something, of course one can - as I do - handle the memmove oneself)

  Maybe I'm the odd one for wanting to do such a thing on a regular
  basis, but something like in the (other) attached patch, I feel,
  might be useful. I know it certainly wasn't the first time I have to
  write that sort of things...

Thanks for the help!

>From c9d5bb194408f22db8ef859203f28c6748e78ab9 Mon Sep 17 00:00:00 2001
From: Olivier Brunel <j...@jjacky.com>
Date: Thu, 12 Apr 2018 18:05:14 +0200
Subject: [PATCH] Fix avltree_deletenode

Signed-off-by: Olivier Brunel <j...@jjacky.com>
 src/include/skalibs/avltree.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/include/skalibs/avltree.h b/src/include/skalibs/avltree.h
index 1ce7385..8234d95 100644
--- a/src/include/skalibs/avltree.h
+++ b/src/include/skalibs/avltree.h
@@ -48,7 +48,7 @@ extern int avltree_newnode (avltree *, uint32_t, uint32_t *) ;
 #define avltree_insertnode(t, i) avltree_setroot(t, avlnode_insertnode(avltree_nodes(t), avltree_totalsize(t), avltree_root(t), i, (t)->dtok, (t)->kcmp, (t)->external))
 extern int avltree_insert (avltree *, uint32_t) ;
-#define avltree_deletenode(t, i) avltree_delete(t, (*(t)->dtok)(avltree_data(t, i)))
+#define avltree_deletenode(t, i) avltree_delete(t, (*(t)->dtok)(avltree_data(t, i),(t)->external))
 extern int avltree_delete (avltree *, void const *) ;
 #define avltree_iter(t, f, p) avlnode_iter(avltree_nodes(t), avltree_totalsize(t), avltree_root(t), f, p)

>From 0c8186bfedc2dfa6d1bd083dafc3ec9a7c46828d Mon Sep 17 00:00:00 2001
From: Olivier Brunel <j...@jjacky.com>
Date: Thu, 12 Apr 2018 18:51:40 +0200
Subject: [PATCH] Add genalloc_delete

Signed-off-by: Olivier Brunel <j...@jjacky.com>
 src/include/skalibs/genalloc.h       |  2 ++
 src/libstddjb/genalloc_delete_size.c | 12 ++++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 src/libstddjb/genalloc_delete_size.c

diff --git a/src/include/skalibs/genalloc.h b/src/include/skalibs/genalloc.h
index da83c2f..acf2bec 100644
--- a/src/include/skalibs/genalloc.h
+++ b/src/include/skalibs/genalloc.h
@@ -28,6 +28,8 @@ typedef stralloc genalloc, *genalloc_ref ;
 #define genalloc_reverse(type, g) stralloc_reverse_blocks((g), sizeof(type))
 #define genalloc_insertb(type, g, offset, s, n) stralloc_insertb((g), (offset)*sizeof(type), (char const *)(s), (n)*sizeof(type))
 #define genalloc_insert(type, g1, offset, g2) stralloc_insert((g1), (offset)*sizeof(type), (g2))
+#define genalloc_delete(type,g,i) genalloc_delete_size((g),sizeof(type),i)
+extern void genalloc_delete_size (genalloc *, size_t, size_t) ;
 #define genalloc_deepfree(type, g, f) genalloc_deepfree_size(g, (freefunc_t_ref)(f), sizeof(type))
 extern void genalloc_deepfree_size (genalloc *, freefunc_t_ref, size_t) ;
diff --git a/src/libstddjb/genalloc_delete_size.c b/src/libstddjb/genalloc_delete_size.c
new file mode 100644
index 0000000..a289000
--- /dev/null
+++ b/src/libstddjb/genalloc_delete_size.c
@@ -0,0 +1,12 @@
+/* ISC license. */
+#include <string.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+void genalloc_delete_size (genalloc *g, size_t s, size_t i)
+  size_t len = g->len / s;
+  if (len > i + 1) memmove (g->s + i * s, g->s + (i + 1) * s, (len - i - 1) * s) ;
+  g->len -= s ;

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